To spread a liquid or a thick substance over a surface. (Cambridge Dictionary)
To publicly accuse someone of something unpleasant, unreasonable, or unlikely to be true in order to harm their reputation. (Cambridge Dictionary)
If you smear a surface with an oily or sticky substance or smear the substance onto the surface, you spread a layer of the substance over the surface. (Collins Dictionary)
A smear is a dirty or oily mark. (Collins Dictionary)
To smear someone means to spread unpleasant and untrue rumours or accusations about them in order to damage their reputation. (Collins Dictionary)
A smear is an unpleasant and untrue rumour or accusation that is intended to damage someone’s reputation. (Collins Dictionary)
A smear or a smear test is a medical test in which a few cells are taken from a woman’s cervix and examined to see if any cancer cells are present. (Collins Dictionary)
Pap (cervical) smear test.
Overview of the Pap Smear Procedure.